During fabrication of liquid crystal display (LCD), after assembling array substrate and color filter substrate, liquid crystal display panels with desired size is obtained by scribing and cutting a large block of liquid crystal panel. As shown in FIG. 1, a cutting groove 2 is formed on surface of glass substrate of the liquid crystal panel along a cutting line by a diamond roller blade 1, which is rolled and cut into the liquid crystal panel under pressure. The cutting groove 2 has a depth of 80˜110 μm in a vertical direction relative to the surface of glass substrate. The glass substrate of the liquid crystal panel has a typical thickness of 0.5 mm˜1.1 mm. Thus after the above cutting process, the whole block of liquid crystal panel with the cutting grooves will be transferred to a break separation stage where it is subjected to a break separation process so as to obtain liquid crystal display panels with final desired size. During the break separation process, the cutting groove 2 is substantially extended in a vertical direction relative to surface of glass substrate.
There are two major kinds of conventional break separation processes including contact break separation such as roller break separation and non-contact break separation.
In roller break separation process, a roller is pressed against surface of glass substrate of array substrate and/or color filter substrate under certain pressure so that the cutting groove is substantially extended in thickness direction of the glass substrate in order to separate panels. In the above process, it is difficult to adjust the pressure. If the pressure is too large, it might damage the panel; if the pressure is too small, the glass debris generated during cutting might remain on the panel and are difficult to remove. Furthermore, it is difficult to control locations of the cutting line of the roller. Therefore, defects such as X line and chipping might occur and lead to panel failure.
In non-contact break separation process, a heated pressurized water vapor is jetted at the cutting grooves and the panels are separated due to cold contraction during temperature drop caused by evaporation of vapor. In the above process, it is difficult to adjust amount of vapor. If the amount of vapor is too less, it might cause incomplete separation; if the amount of vapor is too more, water will be left on the surface of glass substrate. Furthermore, the panel might be contaminated since glass debris generated during cutting will be more likely to attach onto surface of glass substrate due to the adhesiveness of water molecules.